Protamine does not increase risk of stroke in patients with elective carotid stenting

Efficacy and safety of perioperative dual antiplatelet therapy with ticagrelor versus clopidogrel in carotid artery stenting

BACKGROUND

Clopidogrel resistance is associated with increased periprocedural neurologic events after carotid artery stenting (CAS). Ticagrelor offers an improved resistance profile; however, its bleeding risk has not been assessed with CAS. Therefore, we examined the efficacy and safety of perioperative dual antiplatelet therapy with aspirin/ticagrelor vs aspirin/clopidogrel in patients undergoing transfemoral carotid artery stenting (tfCAS) or transcarotid artery revascularization (TCAR).

METHODS

We identified all patients who underwent tfCAS or TCAR in the Vascular Quality Initiative registry from January 2016 to March 2021. We stratified patients by procedure and assessed outcomes using 1:3 propensity score-matched cohorts of patients who received perioperative aspirin/ticagrelor vs aspirin/clopidogrel. The primary efficacy outcome was a composite endpoint of in-hospital stroke/death, and the primary safety outcome was access-related bleeding. As a secondary analysis, we assessed these outcomes after stratifying each cohort by intraoperative protamine use.

RESULTS

Among 17,731 tfCAS patients, 593 (3.3%) received aspirin/ticagrelor and 11,404 (64%) received aspirin/clopidogrel. For the 2065 matched patients, no significant differences were found in the composite endpoint of stroke/death (aspirin/ticagrelor, 4.1%; vs aspirin/clopidogrel, 2.6%; relative risk [RR],1.5; 95% confidence interval [CI], 0.88-2.7) or in the individual endpoints of stroke (2.9% vs 1.8%; RR, 1.6; 95% CI, 0.87-3.0) or death (1.7% vs 1.1%; RR, 1.6; 95% CI, 0.71-3.5). However, aspirin/ticagrelor was associated with a higher risk of bleeding (5.8% vs 2.8%; RR, 2.0; 95% CI, 1.2-3.2). In a subgroup analysis of 297 tfCAS patients (14%) who received intraoperative protamine, no differences remained in stroke/death (1.5% vs 3.9%; RR, 0.38; 95% CI, 0.05-3.0), and there was no longer a difference in bleeding (3.0% vs 2.6%; RR, 1.1; 95% CI, 0.24-5.5). Among 17,946 TCAR patients, 453 (2.5%) received aspirin/ticagrelor and 13,696 (76%) received aspirin/clopidogrel. For the 1618 matched patients, no differences were found in stroke/death (0.7% vs 1.4%; RR, 0.53; 95% CI, 0.16-1.8), stroke (0.2% vs 1.2%; RR, 0.20; 95% CI, 0.03-1.5), death (0.5% vs 0.2%; RR, 3.0; 95% CI, 0.42-21), or bleeding (1.2% vs 1.6%; RR, 0.75; 95% CI, 0.28-2.0). For the 1429 TCAR patients (88%) who received protamine, no differences were found in stroke/death (0.8% vs 1.2%; RR, 0.68; 95% CI, 0.20-2.4) or bleeding (0.6% vs 1.4%; RR, 0.39; 95% CI, 0.09-1.7).

CONCLUSIONS

Compared with aspirin/clopidogrel, aspirin/ticagrelor was associated with a potentially lower risk of stroke/death and bleeding complications after CAS in cases in which protamine was used but a higher risk of these outcomes in the absence of protamine. Given our limited sample size, our analysis should be repeated when more patients are available for study. However, our findings suggest that aspirin/ticagrelor could be a reasonable alternative to aspirin/clopidogrel for both tfCAS and TCAR when protamine is used.

A Meta-Analysis of Using Protamine for Reducing the Risk of Hemorrhage During Carotid Recanalization: Direct Comparisons of Post-operative Complications

Background: Protamine can decrease the risk of hemorrhage during carotid recanalization. However, it may cause severe side effects. There is no consensus on the safety and efficacy of protamine during surgery. Thus, we conduct a comprehensive review and meta-analysis to compare the differences between the protamine and the no-protamine group.

Method: We systematically obtained literature from Medline, Google Scholar, Cochrane Library, and PubMed electronic databases. All four databases were scanned from 1937 when protamine was first adopted as a heparin antagonist until February 2021. The reference lists of identified studies were manually checked to determine other eligible studies that qualify. The articles were included in this meta-analysis as long as they met the criteria of PICOS; conference or commentary articles, letters, case report or series, and animal observation were excluded from this study. The Newcastle-Ottawa Quality Assessment Scale and Cochrane Collaboration’s tool are used to assess the risk of bias of each included observational study and RCT, respectively. Stata version 12.0 statistical software (StataCorp LP, College Station, Texas) was adopted as statistical software. When I2 < 50%, we consider that the data have no obvious heterogeneity, and we conduct a meta-analysis using the fixed-effect model. Otherwise, the random-effect model was performed.

Result: A total of 11 studies, consisting of 94,618 participants, are included in this study. Our analysis found that the rate of wound hematoma had a significant difference among protamine and no-protamine patients (OR = 0.268, 95% CI = 0.093 to 0.774, p = 0.015). Furthermore, the incidence of hematoma requiring re-operation (0.7%) was significantly lower than that of patients without protamine (1.8%). However, there was no significant difference in the incidence of stroke, wound hematoma with hypertension, transient ischemic attacks (TIA), myocardial infarction (MI), and death.

Conclusion: Among included participants undergoing recanalization, the use of protamine is effective in reducing hematoma without increasing the risk of having other complications. Besides, more evidence-based performance is needed to supplement this opinion due to inherent limitations.

Protamine use in transfemoral carotid artery stenting is not associated with an increased risk of thromboembolic events

BACKGROUND

Protamine use in carotid endarterectomy has been shown to be associated with fewer perioperative bleeding complications without higher rates of thromboembolic events. However, the effect of protamine use on complications after transfemoral carotid artery stenting (CAS) is unclear, and concerns remain about thromboembolic events.

METHODS

A retrospective review was performed for patients undergoing transfemoral CAS in the Vascular Quality Initiative from March 2005 to December 2018. We assessed in-hospital outcomes using propensity score-matched cohorts of patients who did and did not receive protamine. The primary outcome was in-hospital stroke or death. Secondary outcomes included bleeding complications, stroke, death, transient ischemic attack, myocardial infarction, and congestive heart failure exacerbation. Bleeding complications were categorized as bleeding resulting in intervention or blood transfusions.

RESULTS

Of the 17,429 patients undergoing transfemoral CAS, 2697 (15%) patients received protamine. We created 2300 propensity score-matched pairs of patients who did and did not receive protamine. There were no statistically significant differences in stroke or death between the two cohorts (protamine, 2.5%; no protamine, 2.9%; relative risk [RR], 0.85; 95% confidence interval [CI], 0.60-1.21; P = .37). Protamine use was not associated with statistically significant differences in perioperative bleeding complications resulting in interventional treatment (0.9% vs 0.5%; RR, 2.10; 95% CI, 0.99-4.46; P = .05) or blood transfusion (1.2% vs 1.2%; RR, 0.92; 95% CI, 0.53-1.61; P = .78). There were also no statistically significant differences for the individual outcomes of stroke (1.8% vs 2.3%; RR, 0.78; 95% CI, 0.52-1.16; P = .22), death (0.9% vs 0.8%; RR, 1.17; 95% CI, 0.62-2.19; P = .63), transient ischemic attack (1.4% vs 1.3%; RR, 1.10; 95% CI, 0.67-1.82; P = .70), myocardial infarction (0.5% vs 0.4%; RR, 1.20; 95% CI, 0.52-2.78; P = .67), or heart failure exacerbation (1.0% vs 0.9%; RR, 1.05; 95% CI, 0.58-1.90; P = .88). Protamine use in patients presenting with symptomatic carotid stenosis was associated with lower risk of stroke or death (3.0% vs 4.3%; RR, 0.69; 95% CI, 0.47-0.998; P = .048), whereas there were no statistically significant differences in stroke or death with protamine use in asymptomatic patients (1.6% vs 1.0%; RR, 1.63; 95% CI, 0.67-3.92; P = .28).

CONCLUSIONS

Heparin reversal with protamine after transfemoral CAS is not associated with an increased risk of thromboembolic events, and its use in symptomatic carotid disease is associated with a lower risk of stroke or death.

The study of transcarotid artery revascularization under local versus general anesthesia with results from the Society for Vascular Surgery Vascular Quality Initiative

Objective

The primary purpose of this study was to examine any potential difference in clinical outcomes between transcarotid artery revascularization performed under local anesthesia compared with general anesthesia by utilizing a large national database.

Methods

The primary outcome of the study was a composite endpoint of postoperative in-hospital stroke, myocardial infarction and mortality following transcarotid artery revascularization for the index procedure. Secondary outcomes included a composite outcome of postoperative in-hospital stroke, transient ischemic attack, myocardial infarction and mortality along with several subsets of its components and each individual component, flow reversal time (min), radiation dose (GY/cm2), contrast volume utilized (mL), total procedure time (min), extended total length of stay (>1 day) and extended postoperative length of stay (>1 day). Statistical analyses employed both descriptive measures to characterize the study population and analytic measures such as multivariable mixed-effect linear and logistic regressions using both unmatched and propensity-score matched cohorts.

Results

A total of 2609 patients undergoing transcarotid artery revascularization between the years 2016 and 2018 in the US were identified, with 82.3% performed under general anesthesia and 17.7% under local anesthesia. The primary composite outcome was observed in 2.3% of general anesthesia patients versus 2.6% of local anesthesia patients ( p = 0.808). The rate of postoperative transient ischemic attack and/or myocardial infarction was 1.6% with general anesthesia versus 1.1% with local anesthesia ( p = 0.511). For adjusted regression analysis, general anesthesia and local anesthesia were comparable in terms of primary outcome (OR: 0.72; 95% CI: 0.27–1.93, p = 0.515). As for the secondary outcomes, no significant differences were found except for contrast, where the results demonstrated significantly less need for contrast with procedures performed under general anesthesia (coefficient: 4.94; 95% CI: 1.34–8.54, p = 0.007). A trend towards significance was observed for lower rate of postoperative transient ischemic attack and/or myocardial infarction (OR: 0.33; 95% CI: 0.09–1.18, p = 0.088) and lower flow reversal time under local anesthesia (coefficient: –0.94: 95% CI: –2.1–0.22, p = 0.111).

Conclusions

Excellent outcomes from transcarotid artery revascularization for carotid stenosis were observed in the VQI database between the years 2016 and 2018, under both local anesthesia and general anesthesia. The data demonstrate the choice of anesthesia for transcarotid artery revascularization does not appear to have any effect on clinical outcomes. Surgical teams should perform transcarotid artery revascularization under the anesthesia type they are most comfortable with.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: optimal management of anticoagulation therapy

BACKGROUND

Clinicians confront numerous practical issues in optimizing the use of anticoagulants to treat venous thromboembolism (VTE).

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians and other health care professionals in their decisions about the use of anticoagulants in the management of VTE. These guidelines assume the choice of anticoagulant has already been made.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 25 recommendations and 2 good practice statements to optimize management of patients receiving anticoagulants.

CONCLUSIONS

Strong recommendations included using patient self-management of international normalized ratio (INR) with home point-of-care INR monitoring for vitamin K antagonist therapy and against using periprocedural low-molecular-weight heparin (LMWH) bridging therapy. Conditional recommendations included basing treatment dosing of LMWH on actual body weight, not using anti-factor Xa monitoring to guide LMWH dosing, using specialized anticoagulation management services, and resuming anticoagulation after episodes of life-threatening bleeding.

Multiple preoperative and intraoperative factors predict early fistula thrombosis in the Hemodialysis Fistula Maturation Study

OBJECTIVE

Early thrombosis (ET) contributes to autogenous arteriovenous fistula (AVF) failure. We studied patients undergoing AVF placement in the Hemodialysis Fistula Maturation Study, a prospective, observational cohort study, using a nested case-control analysis to identify preoperative and intraoperative predictors of ET.

METHODS

ET cases were compared with controls, who were matched for gender, age, diabetes, dialysis status, and surgeon fistula volume. ET was defined as thrombosis diagnosed by physical examination or ultrasound within 18 days of AVF creation. Conditional logistic regression models were fit to identify risk factors for ET.

RESULTS

Thirty-two ET cases (5.3%) occurred among 602 study participants; 198 controls were matched. ET was associated with female gender (odds ratio [OR], 2.75; 95% confidence interval [CI], 1.19-6.38; P = .018), fistula location (forearm vs upper arm; OR, 2.76; 95% CI, 1.05-7.23; P = .039), feeding artery (radial vs brachial; OR, 2.64; 95% CI, 1.03-6.77; P = .043) and arterial diameter (OR, 1.52; 95% CI, 1.02-2.26; P = .039, per mm smaller). The draining vein diameter was nonlinearly associated with ET, with highest risk in 2- to 3-mm veins. Surprisingly, ET risk was lower in diabetics (OR, 0.19; 95% CI, 0.07-0.47; P = .0004), lower with less nitroglycerin-mediated brachial artery dilation (OR, 0.42; 95% CI, 0.20-1.92; P = .029 for each 10% lower) and higher with lower carotid-femoral pulse wave velocity (OR, 1.49; 95% CI, 1.02-2.20; P = .041, for each m/s lower). Intraoperative protamine use was associated with a higher ET risk (OR, 3.26; 95% CI, 1.28-∞; P = .038). Surgeon's intraoperative perceptions were associated with ET: surgeons' greater concern about maturation success (likely, marginal, unlikely) was associated with higher thrombosis risk (OR, 8.09; 95% CI, 4.03-∞; P < .0001, per category change), as were absence vs presence of intraoperative thrill (OR, 21.0; 95% CI, 5.07-∞; P = .0001) and surgeons' reported frustration during surgery (OR, 6.85; 95% CI, 2.70-∞; P = .0004). Decreased extent of intraoperative thrill (proximal, mid or distal third of the forearm or upper arm, based on AVF placement) was also associated with ET (OR, 2.91; 95% CI, 1.31-∞; P = .007, per diminished level). Oral antithrombotic medication use was not significantly associated with ET.

CONCLUSIONS

ET was found to be associated with female gender, forearm AVF, smaller arterial size, draining vein diameter of 2 to 3 mm, and protamine use. Paradoxically, diabetes and stiff, noncompliant feeding arteries were associated with a lower frequency of ET. Absent or attenuated intraoperative thrill, and both surgeon frustration and concern about successful maturation during surgery, were correlated strongly with ET.